A lively dispute exists on which laser source will own the future of material processing. In nearly every debate, one thing is clear: There is no single ideal beam source for industrial lasers. Users will continue to need different beam sources in the future. The industrial sectors are much too different, and the applications for which the various laser technologies are used are much too complex. TRUMPF, as the international market leader in laser technology, offers all of the different technology platforms. “We focus on specific uses and offer our customers the right laser for each application,” states Jens Bleher, managing director of TRUMPF Laser Technology Division.

Whenever new technologies appear on the market, users and experts ask if the new platforms will replace the old tried-and-true approaches. For example, experts prophesied the end of the CO2 laser when the first high-power solid state lasers were introduced. The first diode laser in the kilowatt range with its superior efficiency and compact size was also considered to be the laser beam source of the future for a long time. In retrospect, one thing is clear: Not a single new beam source technology has completely replaced existing, proven technologies. Rather, new technologies have found their own niche among users and have generally expanded the potential of lasers in processing materials.

In the present discussion of whether fibers or disks are the better radiation source, frequently “either/or” decisions are made. A more differentiated consideration of the numerous laser applications for processing materials reveals that there is no such thing as an optimum laser. “Every technology has its advantages that we need to exploit based on the customer’s needs,” notes Bleher. That is why TRUMPF uses every available technology and continues to develop them. This strategy has made the company the vendor with the world’s largest assortment of laser sources, starting with the CO2 laser, then the rod and disk laser, and finally the fiber laser. TRUMPF is able to offer its customers a suitable laser for virtually every application. The product portfolio ranges from lasers for microprocessing (TruMicro), to lasers for welding and cutting complex components (TruPulse, TruFiber), to marking lasers (TruMark), to disk lasers (TruDisk) for demanding welding jobs, and CO2 lasers (TruFlow, TruCoax) that have become indispensable in everyday production.

Fiber lasers for detailed applications, disk lasers for the multi-kilowatt range
Different laser technologies are based on different approaches. Each radiation source has its strengths and weaknesses. The beam quality of both disk and fiber lasers is high, and they are highly effective. “Whereas the strength of the fiber laser is in the low output range, the disk laser is more practical in the high output range,” states Bleher, summarizing the applications for the two solid state lasers. 

Disk lasers with high process reliability
The advantage of the disk laser over the fiber laser in multi-kilowatt applications is obvious. Given its large illuminated area, the power density of the disk laser is not critical, even at a high output. Fiber lasers generate an enormous power density that negatively influences process reliability. Another disadvantage of the fiber laser is its high sensitivity to reflection that frequently arises when processing material with the laser. If a fiber laser resonator experiences reflection, it generally needs to be shut off to protect the laser. Since the resonator of the disk laser is insensitive to reflection even when materials are highly reflective, the user can weld and cut any material without the risk of having to stop production.

Another user benefit is the modular design of the disk laser. Since the customer can exchange the individual modules for service or if a malfunction arises, downtime is minimal, and so are repair costs. Due to the monolithic structure of the fiber laser, the customer cannot exchange defective modules without assistance. This leads to long downtimes.

For applications in the low output range, fiber lasers can be advantageous. This type of laser can easily generate a continuous wave beam in basic mode and achieve superior beam quality relatively easily. “Such a laser is good for welding and cutting thin sheet metal where very fine contours are required,” states Bleher, summarizing the uses of the fiber laser.

CO2 laser remains the first choice for universal cutting machines
For 2-D laser cutting, the CO2 laser remains the gold standard for TRUMPF. “At present, we don’t understand why people feel that the 1 µm wavelength of the solid state laser is preferable. The cutting behavior of the CO2 laser with a 10 µm wavelength offers a high degree of flexibility when cutting sheet metal of different thicknesses,“ emphasizes Bleher. In addition, the high edge quality argues for the CO2 laser as a universal cutting machine.

Technology, application and service – a combined package
In the final analysis, the client always chooses which laser should be used for which application. The laser technology itself is not the primary concern of the customer. The complete technology package, application and service, needs to work for the customer. TRUMPF not only offers the right laser for each application, but also an international service network of approximately 900 service technicians that the customer can call on at any time.

Only the future will reveal how many fiber lasers, disk lasers, rod lasers and CO2 lasers users will employ to process materials. For Bleher, however, one thing is sure: “Given developments in diode technology, the key technology for processing materials with lasers in the near future, the current discussions about the right laser source will appear irrelevant in a few years.“